package AMV.Usb;

/**
 * mamenghao
 * 2022/10/179:25 AM
 */
public class Computer {
   public  Usb usb1;
   public   Usb usb2;
     public Usb usb3;
     public void run(){
         System.out.println("苹果电脑开始运行了");
         if(usb1!=null){
             usb1.service();
         }
         if(usb2!=null){
             usb2.service();
         }
         if(usb3!=null){
             usb3.service();
         }
         System.out.println("电脑运行结束");
     }
}
